Circular Future of Yukawa Unification in Supersymmetric Pati-Salam Model: Stop on Neutralino

Abstract

We explore the low scale implications of SUSY models based on the gauge symmetry SU(4)_CxSU(2)_LxSU(2)_R. We include the non-holomorphic terms arises from the perturbations on D-branes, which also break SUSY. These terms significantly change the implications of Yukawa unification, since they are directly included in the threshold contributions to Yukawa couplings. With these contributions, YU can be compatible with low fine-tuning and yet heavy Higgsino-like LSP, but these solutions receive strong negative impact from the dark matter observations. Besides, in contrast to the earlier results, the NH contributions accommodate heavy gluino masses from about 2.2 to 10 TeV compatible with Yukawa unification. These gluinos can be probed up to about 2.5 in the collider experiments of high luminosity, and to about 6 TeV in future experiments of 100 TeV center of mass energy. In contrast to the gluino mass scales, the NH contributions can drive the squarks of the third family to the light masses. We observe that the Yukawa unification solutions can be compatible with the sbottom mass of about 1.5 TeV, and they are more likely to be tested soon. The stop can also be as light as about 1.5 TeV, and it can be nearly degenerate with the LSP neutralino. Even though these solutions are beyond the sensitivity of the current collider analyses, they can be subjected to be tested in future experiments such as those of Future Circular Collider proposal. We project the current analyses for stop-neutralino degenerate solutions to the Future Circular Collider experiments, and realize that the signal processes with semi-leptonic final states can yield about 5 sigma significance with appropriate cuts on the kinematic variables. Such a large significance can be realized when L ~ 97 fb^-1. We also present a slight improvement by performing BDT analyses, which can yield a similar significance with L ~ 54 fb-1.

Figures (14)

• Figure 1: The threshold corrections to the b-quark Yukawa coupling.
• Figure 2: The topology for the signal processes considered in our analyses.
• Figure 3: The results for YU in correlation with $m_{0}$ (top) and $\tan\beta$ (bottom) for the holomorphic (left) and NH (right) cases. All the solutions are compatible with REWSB and LSP neutralino condition. The green points satisfy the mass bounds and constraints from rare $B-$meson decays. The red points form a subset of green, and they represent the relic density solutions compatible with the Planck measurements within $5\sigma$. The horizontal dashed lines indicate the solutions with $R_{tb\tau} = 1.1$, and the points below these lines are identified as the YU solutions.
• Figure 4: The plots in the $R_{tb\tau}-m_{\tilde{g}}$ (top) and $R_{tb\tau}-m_{\tilde{t}_{1}}$ (bottom) planes for the holomorphic (left) and NH (right) cases. The color coding and the dashed line represent the solutions as described in Figure \ref{['fig:YUm0tanb']}. The gluino mass bounds are not applied to the top planes, while these bounds are represented with vertical dashed lines.
• Figure 5: The plots in the $R_{tb\tau}-\mu$ in the holomorphic (left) and NH (right) cases. The colors and the dashed lines represent the solutions as described in Figure \ref{['fig:YUm0tanb']}